1. Field of the Invention
The present invention is directed generally to radio management and, more particularly, to a system and method for controlling multiple radios within a single device.
2. Description of the Related Art
Wireless communication has evolved from simple single-mode voice communication to highly sophisticated multi-mode communication devices used for voice communication, email, web page access, video download, streaming media transmission and reception, and the like.
While the early single-mode devices contained a single transceiver, modern wireless devices often have multiple transceivers to allow it to communicate using different communication frequencies and/or communication protocols. For example, a wireless device may include a radio for communication with a service provider using Code Division Multiple Access (CDMA) as well as a radio for WiFi communication and yet another radio for WiMAX communication.
If all three communication types are available, a wireless device may have a predetermined or user-selected preference for communication. For example, a wireless device may prefer communication via WiMAX, but will switch to WiFi if WiMAX is unavailable. If neither WiMAX nor WiFi are available, the device may resort to communication using CDMA.
To conserve battery power, a wireless device will turn off unused radios. However, when communicating using a less desired communication protocol, the wireless device may periodically power up the other radios to search for a base station with which to communicate using a more preferred communication protocol. Currently, the operation of multiple radios requires scanning for available radio frequencies for each of these multiple communication protocols. This periodic power-up of multiple radios can result in an undesirable surge in power consumption. For a battery-operated device, this is a drawback. In addition, when a particular transceiver enters into a power-up state, it must sometimes search over a broad range of frequencies to detect possible base stations with which to register. This can cause further undesirable consumption of battery power.
To avoid the undesirable consumption of battery power, some conventional wireless devices use a back-off algorithm when searching for alternative base stations. In a typical back-off algorithm, the wireless device periodically powers up one or more radios to search for a more desirable base station with which to communicate. However, if the wireless device is unable to find a more desirable base station, it will search less and less frequently as time goes on. That is, the wireless device backs off in the frequency with which it searches for more desirable base stations with which to communicate.
While the back-off algorithm may conserve battery power, it may also delay the reacquisition of a more desirable base station with which to communicate. Therefore, it can be appreciated that there is a significant need for a technique that will improve the reacquisition of more preferable base stations. The present disclosure provides this and other advantages, as will be apparent from the following detailed description and accompanying figures.